The present invention generally relates to a magnetic disk drive capable of recording and reproducing data out of a magnetic disk or similar medium by moving a magnetic head mounted on an actuator arm over the medium and, more particularly, to a mechanism for fixing the head in place when the disk drive is not operated.
A hard disk drive or similar magnetic disk drive is extensively used to record and reproduce data out of a magnetic disk or similar medium. It is a common practice with this kind of disk drive to position and fix a magnetic head thereof above the parking area of a medium when the disk drive is not in operation, thereby protecting the data recording surface of the medium. The head has to be fixed in such a position while the power supply is in an OFF state, and various implementations have heretofore been proposed for such a purpose. Among them, the implementation using a magnet, i.e., fixing the head by the magnetic force of a magnet is simple in construction.
Specifically, the magnetic force acts between part of a movable portion movable integrally with an actuator arm on which the head is mounted and a position which part of the movable portion faces when the head lies over the parking area of the medium. As a result, the movable portion and, therefore, the head are fixed in place.
However, the conventional magnet scheme described above has the following problem. Since the parking area and the data storage area of the medium adjoin each other, the position to which the movable portion should be moved during recording or reproduction and the position where it should be fixed by the magnet adjoin each other. Therefore, the magnet tends to urge the movable portion toward the fixing position even during recording or reproduction. This is especially true when a magnet exerting a strong force is used to firmly fix the head in place. Such a force of the magnet prevents the head from being accurately positioned.